The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1983
Filed:
Oct. 21, 1981
Joseph S Wisnouskas, Grand Island, NY (US);
Roland Ho, Wayne, PA (US);
Occidental Chemical Corporation, Niagara Falls, NY (US);
Abstract
An improved process is provided for preparing highly purified phosphorus acid from industrial waste materials which are produced as by-products from the manufacture of sodium hypophosphite. Such industrial waste materials contain substantial quantities of calcium phosphite, and appreciable quantities of various metals such as iron, magnesium, aluminum and arsenic. The process of the present invention comprises, in a preferred embodiment thereof, reacting a slurry of said waste materials with sodium carbonate to produce calcium carbonate as a precipitate and a solution of sodium phosphite. The sodium phosphite solution is then passed through a cation ion exchange resin in the hydrogen form to produce a highly purified phosphorus acid product having significantly reduced quantities of metallic impurities.